1. Field Of The Invention
This invention relates to a tube connecting device, more particularly to an improved tube connecting device which can be easily installed and which provides firm and stable connection between two tubes.
2. Description Of The Related Art
A conventional tube connecting device has been disclosed in U.S. Pat. No. 5,295,717 by the applicant of the present invention. The conventional tube connecting device includes first and second tubular connector members, a pair of press arms, a pair of retaining seats and a pair of retaining units. The first connector member has a receiving end portion formed with a pair of opposite radial openings and an extension end portion to be connected to a corresponding tube. The second connector member has an insert end portion which extends into the receiving end portion and an engaging end portion to be connected to a corresponding tube. The insert end portion has an outer surface which is formed with an annular peripheral groove that is registered with the radial openings. Each of the press arms has one end mounted pivotally to the first connector member adjacent to a respective one of the radial openings and formed with a cam face, and is pivotable to a locking position in which the cam face thereof extends into the peripheral groove via the respective radial opening so as to press against the second connector member at the annular groove in order to secure the second connector member to the first connector member. Each of the retaining seats projects outwardly from the first connector member and is disposed below a respective one of the radial openings. Each of the retaining seats has an inwardly and downwardly inclined side surface and a bottom formed with a vertical blind bore. Each of the press arms has an inner side which is formed with a longitudinal positioning seat. The positioning seat is formed with an axial positioning bore which is aligned with the blind bore in a respective one of the retaining seats when the press arm is in the locking position. Each of the retaining units includes a positioning rod which is provided slidably in the positioning bore of a respective positioning seat and which has first and second end portions that extend out of the positioning bore, a biasing unit which is disposed in the positioning bore of the respective positioning seat and which biases the positioning rod so that a tip of the first end portion is displaced normally from a pivoting axis of a respective press arm by a distance equal to that between a plane lying on the inclined side surface of a respective retaining seat and the pivoting axis of the respective press arm, and a pull ring which is secured on the second end portion of the positioning rod. The first end portion of each of the positioning rod extends into the blind bore of the respective retaining seat when the respective press arm is in the locking position.
Note that the retaining seats and the positioning rods are exposed even when the press arms are in the locking position. Therefore, damage and deformation of the positioning rods and the retaining seats is likely to occur when a moving object strikes the press arms while the latter are in the locking position.
In addition, the manner in which the tip of the first end portion of each positioning rod contacts the inclined side surface of the respective retaining seat when the corresponding press arm is moved to the locking position sometimes results in unsmooth movement of the press arms.